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(No Model.)

J. A KIMBALL. DENTAL GRINDING DISK AND HOLDER.

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I are mounted on a mandrel, which is carried able, for the'reason, among others, that parts parts not detachable.

the new is in'place, the collar is forcibly UNITED STATES J. A LBERT KIMBALL,

PATENT v OFFICE.

on NEW YORK, N. Y'.

DENTAL GRINDING-DISK AND HOLDER.

SPECIFICATION forming part of Letters Patent No. 367,211, dated July 26, 1887.

Application filed November 26, 1886.

1:0 all whom it may concern:

Be it known that I, J. ALBERT KIMBALL, residing in the 'city and county of New York, in the State of New York, dentist, have invented a certain new and useful Improvement in Grinding-Disks and Holders Therefor, adapted for dentists use, of which the following is a speci- The-invention relates to the small disks of stout paper or analogous cheap material coated with sand or emery or the like on one or both sides, which are employed to remove small portions and to polish surfaces. The disks in the hand-piece, and is driven by a flexible shaft connecting with the dental engine. The disks are in their nature short-lived. The stiffness of the material is greatly promoted by the centrifugal force when it is rotated at high -ve1ocities; but the surface becomes smoothed and the stiffness destroyed after a short period of use. It is necessary to renew them frequently.

The means heretofore employed to hold the disk and to efiect the renewal are object-ionother than the disk are detachable and liable to be lost. I have devised a holderhaving' I have devised a modification of the disk adapted to be engaged thereby. The disk is self-centering.

I make the mandrel with the head permanently connected. I make the disk with an opening considerably larger than usual. The excess of the opening beyond that required for the neck of the mandrel is all on one side of the center. The construction allows the disk to be slipped past the fixed head of the mandrel with facility and to be centered promptly and certainly.

I have devised a mandrel having a movable collar acting against the inner face of the head and capable of being moved away from the head. This movement is effected to liberate the old disk and to introduce a new one. After pressed outward, grasping the disk between itself and the fixed head. I force it out by a screw action. I I

In what I esteem the most complete form of the invention the movable collar is compelled to turn with the mandrel, and either the collar or the head is provided with spurs, the opsupported thereon.

Serial No. 219,868. (No model.)

posite part being correspondingly recessed. These spurs prick through the disk and contribute,with the direct grasp between the collar and head, to maintain a firm hold on the disk and compel its revolution.

The accompanying drawings form a part of this specification, and represent what I consider the best means of carrying out the invention.

Figure 1 is an end view of the holder with the disk in place; Fig. 2 is a side view of the same with the hand-piece in which the mandrel is held for operation. This shows the holder closed. The succeeding figures are on a larger scale. Fig. 3 is a side view showing the holder open. Fig. 4 is a corresponding cross section on the line as x in Fig. 3. Fig. 5 is a corresponding cross-section on the line y y in Fig. 3. Fig. 6 is a side view showing a modification. Fig. 7 is a face view of the disk detached. Figs. 8 and 9 are corresponding views showing modifications.

Similar letters of reference indicate corresponding parts in all the figures where they occur.

Referring to Figs. 1 to 5, inclusive, A is the ordinary hand-piece, and B the ordinary 8o flexible connection through which the revolution is imparted to the mandrehwhich is sup ported in the hand-piece with freedom to revolve rapidly.

D is the mandrel. D isa head permanently s fixed thereon. It is of sufficient diameter and thickness to afford a reliable holdingsurfaee to'act against the outer face of the disk. A portion of the mandrel near the head is squared. Beyond this it is cylindrical.

D is a stout pin set in the cylindrical portions, as represented.

M is the disk, of the ordinary or any suitable material, coated with grinding material of the desired grade on one or both faces. It is punched or otherwise provided with an aperture, mm, the part at being in the center and the part at, shaped as shown, being out of center. v

E is a movable slide fitting on the squared rco portion and of sufficient length to be steadily It is capable of being moved endwise, but not of revolving. Its outer end constitutes a collar to act against the inner face of the disk. It is equipped with spurs e, which, when pressed outward against the head D, match in corresponding recesses therein.

G is a sleeve, which performs important functions. It is free to slide endwise, and also to be partially revolved on the cylindrical portion of D. It is provided with a peculiarlyformed slot, 9 g. The portion extends longitudinally. The portion 9 is an L-extension of g and arranged obliquely thereto. The pin D stands in this slot (7. 7.

To operate the invention, the sleeve G and slide Eare moved inward and a disk, M, is applied in an inclined position. It is presented in such position as to slip the head D through the aperture in, and it is readily brought into the required position within the fixed head with the mandrel centered in the portion at of the aperture. Next, the sleeve G is moved outward, bringing the slide Einto forcible contact with the inner face of the disk and thrusting its spurs 0 through the disk into the corresponding recesses in the inner face of the head. Lastly, the sleeve G is turned on the mandrel D as a center. This movement brings the pin D into the L part 9 of the slot. This portion being inclined, acts screwwise to force the sleeve axially. This presses the slide E strongly outward, and insures a firm retention of all the parts in the position in which they are left.

The mandrel is operated and the disk brought to bear upon the surfaces of the teeth or of fillings, performing the usual functions.

Vhen it is desired to substitute a new disk, the sleeve G is first turned partially around to the left, bringing the pin D" in the straight portion 9 of the slot. ]tis then moved axially to the full extentallowed by the slot r followed by the slide E. This liberates the former disk, which is then easily removed and a new one applied. Now, theoperation of securing is repeated. The sleeve G, with the slide E, is moved directly outward, and the sleeve G turned to the right to lock the parts by engaging the pin D again in the inclined slot 5 Modifications may be made in the forms and proportions. I can make the head Doval instead of circular. In such case I would make the collar or outer end of the slide E of a corresponding form.

Parts of the invention can be used without the whole. I can dispense with the spurs c. In such case the recesses in the inside of the head D may be omitted.

I can roughen the surfaces by making them file-eutthat is to say, the inner surface of the head I) and the collar on the outer end of the slide E may be crossridged like a file.

Fig. 6 shows a modification in which the fixed head D is retained on a mandrel; but, instead of the slide E and sleeve G, a screwthreaded tube is applied, engaged with corresponding screw-threads on the mandrel. I can use this form shown in Fig. 6 with a slide corresponding to E between the tube and the disk. Such would allow the use of the spurs e,- or I can use the form shown in Figs. 1 to 5 without the squared portion of the mandrel and without the slide E, letting the outer end of G press directly against the disk. In both these cases the spurs corresponding to 0 must of course be omitted.

\Vhen the slide E is retained, it may be held against revolving by other meansthan the square form of the mandrel engaging in the correspondingly-shaped hole. The cross-seetions may be triangular or of any form other than circular. \Vhen the mandrelis of square section, I can make the portion 'lit of the aperture of corresponding form. Such a form is indicated in Fig. 9.

The mandrel may, if desired, be removed from the holder and thrust temporarily into a suitably-shaped socket, (not shown,) to aid in holding it while the sleeve G is turned strongly to the right or left. The sleeve may be roughened on the exterior, to aid in turning it conveniently by the thumb and finger.

My invention holds the disk with great strength. In the form shown in Figs. 1 to 5 it allows a rapidppening and closing of the holder with great security when closed. The resistance of the grinding tends to lock the device tighter.

Vith any of the modifications the holder is always selfcontained. There are no parts which require to be separated or are in fact separable.

My experiments indicate that no inconvenience will result from the slight want of balance in the light disk.

I claim as my invention 1. The disk M, provided with grinding material on one or both faces, and having an aperture, m m, adapted to allow the passage of the mandrelhead, and also to center the disk, all substantially as herein specified.

2. A mandrel having a fixed head, in combination with a collar movable on the mandrel, and with means, substantially as specified, for urging the collar forcibly outward, arranged forjoint operation relatively to each other and to a disk of soft material embraced between it and the collar, as herein specified.

3. The slide E and sleeve G, with its slot {1 g, in combination with each other and with the mandrel D, having a head, D, and a pin, D, arranged to serve relatively to each other and to asoft disk, M m m, as herein specified.

4. The mandrel D, permanently fixed head D, slide E, soft disk M m m, and spurs c, in combination with each other and with the pin D sleeve G g g, holder A, and flexible connection B, for communicating a rapid rotary motion, all arranged for joint operation, as herein specified.

In testimony whereofl have hereunto setmy hand, at New York city, this 24th day of November, 1886, in the presence of two subscribing witnesses.

J. ALBERT KIMBALL. IVitnesses:

CHARLES R. SEARLE, H. H. J OHNSTONE. 

